216542 has 4 divisors (see below), whose sum is σ = 324816. Its totient is φ = 108270.

The previous prime is 216523. The next prime is 216551. The reversal of 216542 is 245612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a plaindrome in base 16.

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54134 + ... + 54137.

It is an arithmetic number, because the mean of its divisors is an integer number (81204).

2²¹⁶⁵⁴² is an apocalyptic number.

216542 is a deficient number, since it is larger than the sum of its proper divisors (108274).

216542 is a wasteful number, since it uses less digits than its factorization.

216542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108273.

The product of its digits is 480, while the sum is 20.

The square root of 216542 is about 465.3407353757. The cubic root of 216542 is about 60.0501432677.

The spelling of 216542 in words is "two hundred sixteen thousand, five hundred forty-two".